move show_pack_info() where it belongs
[git/git.git] / pack-check.c
1 #include "cache.h"
2 #include "pack.h"
3 #include "pack-revindex.h"
4
5 struct idx_entry
6 {
7 const unsigned char *sha1;
8 off_t offset;
9 };
10
11 static int compare_entries(const void *e1, const void *e2)
12 {
13 const struct idx_entry *entry1 = e1;
14 const struct idx_entry *entry2 = e2;
15 if (entry1->offset < entry2->offset)
16 return -1;
17 if (entry1->offset > entry2->offset)
18 return 1;
19 return 0;
20 }
21
22 static int verify_packfile(struct packed_git *p,
23 struct pack_window **w_curs)
24 {
25 off_t index_size = p->index_size;
26 const unsigned char *index_base = p->index_data;
27 SHA_CTX ctx;
28 unsigned char sha1[20], *pack_sig;
29 off_t offset = 0, pack_sig_ofs = p->pack_size - 20;
30 uint32_t nr_objects, i;
31 int err = 0;
32 struct idx_entry *entries;
33
34 /* Note that the pack header checks are actually performed by
35 * use_pack when it first opens the pack file. If anything
36 * goes wrong during those checks then the call will die out
37 * immediately.
38 */
39
40 SHA1_Init(&ctx);
41 while (offset < pack_sig_ofs) {
42 unsigned int remaining;
43 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
44 offset += remaining;
45 if (offset > pack_sig_ofs)
46 remaining -= (unsigned int)(offset - pack_sig_ofs);
47 SHA1_Update(&ctx, in, remaining);
48 }
49 SHA1_Final(sha1, &ctx);
50 pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
51 if (hashcmp(sha1, pack_sig))
52 err = error("%s SHA1 checksum mismatch",
53 p->pack_name);
54 if (hashcmp(index_base + index_size - 40, pack_sig))
55 err = error("%s SHA1 does not match its inddex",
56 p->pack_name);
57 unuse_pack(w_curs);
58
59 /* Make sure everything reachable from idx is valid. Since we
60 * have verified that nr_objects matches between idx and pack,
61 * we do not do scan-streaming check on the pack file.
62 */
63 nr_objects = p->num_objects;
64 entries = xmalloc(nr_objects * sizeof(*entries));
65 /* first sort entries by pack offset, since unpacking them is more efficient that way */
66 for (i = 0; i < nr_objects; i++) {
67 entries[i].sha1 = nth_packed_object_sha1(p, i);
68 if (!entries[i].sha1)
69 die("internal error pack-check nth-packed-object");
70 entries[i].offset = nth_packed_object_offset(p, i);
71 }
72 qsort(entries, nr_objects, sizeof(*entries), compare_entries);
73
74 for (i = 0; i < nr_objects; i++) {
75 void *data;
76 enum object_type type;
77 unsigned long size;
78
79 data = unpack_entry(p, entries[i].offset, &type, &size);
80 if (!data) {
81 err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
82 sha1_to_hex(entries[i].sha1), p->pack_name,
83 (uintmax_t)entries[i].offset);
84 break;
85 }
86 if (check_sha1_signature(entries[i].sha1, data, size, typename(type))) {
87 err = error("packed %s from %s is corrupt",
88 sha1_to_hex(entries[i].sha1), p->pack_name);
89 free(data);
90 break;
91 }
92 free(data);
93 }
94 free(entries);
95
96 return err;
97 }
98
99 int verify_pack(struct packed_git *p)
100 {
101 off_t index_size;
102 const unsigned char *index_base;
103 SHA_CTX ctx;
104 unsigned char sha1[20];
105 int err = 0;
106 struct pack_window *w_curs = NULL;
107
108 if (open_pack_index(p))
109 return error("packfile %s index not opened", p->pack_name);
110 index_size = p->index_size;
111 index_base = p->index_data;
112
113 /* Verify SHA1 sum of the index file */
114 SHA1_Init(&ctx);
115 SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
116 SHA1_Final(sha1, &ctx);
117 if (hashcmp(sha1, index_base + index_size - 20))
118 err = error("Packfile index for %s SHA1 mismatch",
119 p->pack_name);
120
121 /* Verify pack file */
122 err |= verify_packfile(p, &w_curs);
123 unuse_pack(&w_curs);
124
125 return err;
126 }